Mariposa, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

901
FXUS66 KHNX 292321
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
421 PM PDT Thu May 29 2025

.UPDATE...
Updated aviation section.

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.KEY MESSAGES...
1. A Heat Advisory is in effect for the San Joaquin Valley,
Kern River Valley, lower Sierra Foothills, and West Side Hills
valid from 11 AM Friday through 7 AM Sunday.

2. Widespread Moderate to Major Heat Risk is expected across
the lower elevations of the region.

3. A disturbance over the weekend will allow for the development
of strong winds over the mountains and across the Eastern Mojave
Slopes of the Kern County Mountains early next week.

4. Mountain thunderstorms are possible this weekend, with
a potential for widespread mountain storms on Sunday.

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.DISCUSSION...
High pressure ridge now becoming the dominate weather feature
across the West. With this, temperatures will see a significant
rise over the next several days as we enter into our first heat-
wave. In addition to the heat, the weather pattern aloft is also
showing a weak disturbance sitting off of the Southern
California Coast. While the upper low will be too far provide
Central California with any weather, its position will help
draw-up moisture from Tropical Storm Alvin as thunderstorms
spread across the Mojave Desert and over the Sierra Nevada.
Along with the heat, another disturbance moving into the region
later this weekend will support strong winds and making the
mountains hazards for travelers.

Ensemble Probability of Exceedance (PoE) of reaching 90 degrees
today sits between 45% and 80% across the San Joaquin Valley.
By Friday, PoE of 90 degrees will see a significant jump to near
100% and the focus than turns to the percentages of reaching
100 degrees. PoE of reaching 100 degrees on Friday now sits at
50% to near 90% and widespread 100 degrees are likely. PoE
values increase further on Saturday as the focus than changes to
PoE of 105 degrees. On Saturday, PoE of 105 degrees drops back
to Thursdays range of 45% to 80%. With this, some locations
across the San Joaquin Valley are likely to see near 105 degrees
before the cool-down on Sunday. A Heat Advisory in effect for
Friday and Saturday. Another disturbance knocks-down
temperatures next week as values drop to or below seasonal
normal values before warming again later next week.

Ensemble mean instability bottom out to near zero today and
Friday before rising over the weekend. Probability of
Thunderstorm sits between 5% and 15% Saturday ahead of another
disturbance later in the weekend. While ensemble mean upper-air
analysis has backed off on the strength of next weeks
disturbance, the westerly flow will not favor a deep penetration
of subtropical moisture over the Sierra Nevada this weekend.
Strong winds from the disturbance and limited moisture (for
thunderstorms) will increase fire weather concerns this weekend
and into Monday. Probability of Thunder does go up to near 20%
over the weekend. The disturbance then exits the region early
next week as the flow will inhibit convection and the heat.

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.AVIATION...
00Z Update:

VFR conditions will prevail for the next 24 hours across the
Central California Interior.

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.AIR QUALITY ISSUES...
ISSUED:  05/29/2025 14:54
EXPIRES: 05/30/2025 23:59
None.



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.CERTAINTY...

The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is medium.

Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 11 AM Friday to 7 AM PDT Sunday for
CAZ300>321-324-332.
&&

$$

public...Molina
aviation....SM

weather.gov/hanford